1. Field of the Invention
The present invention relates to a technique of pressing a transfer film onto printed sheets of paper to transfer thereon gold foil, embossed patterns, hologram patterns, and the like, thereby to increase added value of the printed surfaces, and more particularly, to a speed control method and a speed control apparatus for a transfer device, which performs control of the running speed of a transfer film, which is held in running state subsequent to start from running stopped state.
2. Related Art
There is already proposed a gloss finishing apparatus for providing added value to printed sheets of paper in the above-mentioned manner. The apparatus includes a varnishing unit that applies an ultraviolet curable resin varnish (also simply referred to as “a varnish”) onto the printed sheets of paper printed at a printing unit and a hologram forming unit that presses a transfer film for transferring onto the printed sheets of paper varnished at the varnishing unit. The hologram forming unit includes an impression cylinder for conveying printed sheets of paper, a pair of pressing rollers for pressing a film onto the printed sheets of paper on the impression cylinder and a UV (ultraviolet) irradiation unit for curing varnish when the film is held pressed onto the printed sheets of paper with the pressing rollers, in which the pair of pressing rollers are designed to be capable of moving upward relative to the impression cylinder into a retracted position and moving close to the impression cylinder into a pressing position, so that when hologram forming (surface treatment) is not performed, the pressing rollers are moved upward relative to the impression cylinder and positioned at the retracted position (cf. Japanese Patent Application Laid-open No. 2006-315229, FIGS. 1 and 2).